A known example of an element that detects current flowing through a line is a current transformer. A current transformer is usually configured as a transformer where wire is wound on a toroidal core. This results in the size of a component being large, and there are cases where it is difficult to use a current transformer in devices where a smaller size and lower height are desired. An example of a small and thin transformer is a laminated transformer described in Japanese Unexamined Patent Application Publication No. 2004-257964, for example. The laminated transformer described in Japanese Unexamined Patent Application Publication No. 2004-257964 is a surface-mounted electronic component formed by laminating magnetic sheets on which conductor patterns are printed, to configure a transformer.